RAPISARDA Viviana Andrea
congresos y reuniones científicas
Biofilm formation inhibition by PhoB is regulated by polyphosphate levels in Escherichia coli
GRILLO-PUERTAS, M.; RINTOUL, M. R.; RAPISARDA, V. A.
Congreso; L Annual Meeting of SAIB (Argentine Society for Biochemistry and Molecular Biology); 2014
PhoB, the regulator of the two-component system phoBR that responds to media phosphate (Pi) limitation, was described as an inhibitor of biofilm formation. PhoB negatively regulates c-di-GMP, a second-messenger involved in the molecular decision between planktonic motile and biofilm-associated bacterial lifestyles. Polyphosphate (polyP) in Escherichia coli stationary phase are modulated by media Pi concentration and its degradation triggers biofilm formation via LuxS quorum sensing system. The aim of this work was to investigate if polyP levels in stationary phase could regulate PhoB, influencing biofilm formation capacity. E. coli cells were statically cultured in minimal medium varying Pi concentration at different time of growth at 30ºC. For biofilms assays the Cristal violet technique was carried out. Results show that phoBR mutant forms biofilm independently of the media Pi concentration, conversely to diguanilates cyclases deficient strains that never form biofilm. When polyP level was present in stationary phase, a high alkaline phosphatase activity was observed as an indicator of PhoB activation. Varying media Pi concentration, we demonstrate that fluctuation of polyP levels in stationary phase could be involved in PhoB activation/repression with the consequent regulation of biofilm formation mediated by c-di-GMP and AI-2.